Which method ensures confidentiality of data exchanged over a REST API in transit?

TLS (Transport Layer Security) encrypts the entire communication channel between a client and a server, ensuring confidentiality of data in transit. This means that even if an attacker intercepts the data packets, they cannot read the content without the decryption key. Using the POST method instead of URL-encoded GET primarily addresses data visibility in logs and browser history, not encryption during transit. Digest-based authentication provides integrity and authentication but does not encrypt the data payload itself. Base64 encoding is a method for representing binary data in ASCII format; it is not an encryption technique and offers no confidentiality.